Shaft-centering device.



E. S. FERRIS.

SHAFT OENTERING DEVICE.

INVENTOR.

WITNESSES.-

ATTORNEY.

1 UNITED STATES PATENT oEErcE.

EDGAR S. FERRIS, OF HOLYOKE, MASSACHUSETTS, ASSIGNOR OF ONE-THIRD TO CHARLES HOUSE AND ONE-THIRD TO GEORGE A. WHITTEMORE, BOTH 0F HOLYOKE,

MASSACHUSETTS.

SHAFT-CENTERING DEVICE.

Specification of Letters Patent.

Patented Mar. 29, 1910.

This invention relates to improvements in I devices for instruments for quickly and accurately finding the center of a line of shafting.

The objects of the invention are: (1) to provide means whereby the center of a line of shafting may be quickly and accurately projected onto the floor below the shafting; (2) to produce a device that can be used and placed on the line of shafting at any longitudinal part of its length without regard to the diameter of the shafting, or whether various lengths of the same are composed of different diameters; (3) to provide means whereby a plumb-bob can be readily adjusted near the floor or at any convenient height therefrom in the space between the floor and shafting.

In this class of devices as heretofore constructed, it has been the common practice to suspend a plumb-line, by means of a suitable Weight, so as to just touch or graze the side of the shafting, and then mark on the floor a point indicating the curved side of the shafting; then caliper the shafting and measure back from the point on the floor a distance equal to the radius of the shaft. These several steps are very slow and more or less inaccurate since errors are very apt to arise in taking the various measurements, and the larger the number of measurements re uired to be taken, the greater the probabilllty of mistakes in effecting the final resu t.

Broadly stated, my invention comprises an arc-shaped member having mounted on the inner curved part thereof a pair of antifriction rollers which are adapted to engage the upper curved surface of the shaft to be centered, and suitably attachin to the areshaped member the plumb-bob or weight that can be readily adjusted at or near the floor, whereby the weight of the bob will cause the device to readily come to rest or to a state of equilibrium.

The invention further consists in providing means for adapting the same to shafts of different diameters.

In the drawings forming part of this application,Figure 1 is a perspective view showing the manner in which the instrument is used, and illustrating the same, as located on a line of shafting. Fig. 2 is an end View of Fi 1. Fig. 3 is a detail view of the means for clamping the plumb-bob line, whereby the bob may be quickly suspended at any suitable distance from the floor. Fig. 4 is an attachment whereby the device can be used on shafts of greater diameters and Fig. 5 is a view of the parts separated that are in Fig. 4 shown connected.

Referring to the drawings in detail, a designates the arc-shaped member that is provided on the inner curved portion thereof with a pair of anti-friction rollers b of hardened steel for engaging the upper curved surface of the shaft to be centered. These rollers are supported in ears 0 suitably connected to the part a, or they may be made integral therewith. The outer ends of the arc-shaped member a are provided with apertures or openings (Z to which links e and f are attached, the link f being furnished with a hook-shaped end 7. These links are connected to a triangular shaped plate member g, as shown, and looped through the eye h of this member 9 is a cord 2' to one end of which is attached the plumb-bob j, and to the other end of the cord z is attached a clamping device is which is composed of a central plate on on which are pivotally supported the spring-actuated cord clamping members 0.

p designates springs located between the plate m and the clam ing members 0 for normally pressing the in-turned finger ends of the clamping members 0 toward each other, as shown in full lines in Fig. 3, for grasping the cord 2'. The dotted lines in this figure indicate the position of the cordclamping members 0 when in the non-clamping position, that is when the cord 2' is free to run through the eye it in the plate member g for raising and lowering the plumbbob.

The device illustrated in Figs. 1 and 2 clearly indicates how the same is employed in centerin a shaft and may be briefly described as fbllows: The weight of the plumbbob 7' causes the rollers b to move transversely on the upper curved surface of the shaft, that is to say, the rollers will so position themselves in relation to the vertical plane, indicated at (6 passing through the axis of the shaft, that they will come to rest or a state of equilibrium on opposite sides of this plane at equal distances therefrom, as indicated in F ig. 2 at 1", since the flexible connecting means between the plumb-bob and supporting bar will readily permit the parts to bend relative to each other. It is therefore clear that the lower end of the plumb-bob, where it engages the floor, will accurately project the center line of the shaft to the floor below, and this, without regard to the diameter of. the shaft, as clearly shown in Fig. 2. The cord 71, if projected upward, will pass through the center of the shaft and bisect the base of the tri angle, shown in dotted. lines, and designated at r, 1". In locating several points on the floor below the line of shafting, it is only necessary to disengage the hook f of the link from its eye d in the part a, and remove the device from the shafting, when it can readily be replaced by simply rehooking the link, wherever it is desired to locate another point on the floor.

Referring now to Figs. 4 and 5, in which a slight modification of my device is shown: each end of the arm a is provided with two angular-shaped slots .9. t designates an extension member having the same curvature as the arm a and in one face thereof are located pins u that are adapted to enter the slots 8, as shown in Fig. 4, in the assembled position, the operation of which is readily understood.

It is understood that I do not limit myself to the size and shape of. the parts. shown, and that any equivalent means of accoinplishing the same results is understood to be within the scope of my improvements.

What I claim, is

1. In a device for determining the location of the center of, a shaft, in combination, an arc-shaped supporting member provided on its inner curved surface with anti-friction supporting rollers, the opposite ends of the arc-shaped member having attached thereto means for supporting a plumb-bob, said means including a pair of links, and clamping means for adjustably supporting the plumb-bob at different elevations.

2. In a shaft-centering device comprising a suitable member for supporting a plumbbob, and provided with slots in the end portion thereof, extension members for the plumb-bob supporting member, said. members having pins for engaging the slots in the bobsupporting member, and. means, including a pair of spring-pressed clampingfingers, for varying the height of the plumbbob from the floor.

8. In a shaft-centering device, in combination with a plumb-bob supporting member, arcuate in shape, and provided with anti-friction devices on its inner curved.

edge, flexible connecting means between the arc-shaped member and the plumb-bob, said connections including a pair of links attached to the opposite ends of the plumbbob supporting member, and an intermediate plate member to which the links and the plumb-bob are connected, and spring pressed gripping in-turned fingers for engaging the fleXible bob-supporting member,

as described.

4:. A shaftcentering device having in combination with a supporting member for engaging the shaft tobe centered, a plumbbob, means for connecting the same to said member, said means including link members attached to the opposite ends of said shaftengaging member, a plate to which the link members are attached, connecting means between the plate and bob, and. means interposed in the connecting means for varying the position of the bob, substantially as described.

EDGAR S. FERRIS. WVitnesses:

K. I. CLEMoNs, H. IV. BOWEN. 

